High-pressure steam turbine



March 18, 1930. w PAPE I 1,750,814

HIGH PRESSURE STEAM @URBIN'E I Filed Feb. 10, 1925 Jhvenlor: %%Z4 6% Patented Mar. '18, 1930 UNITED STATES.

PATENT :LOFFLCEI WILHELM PAPE, OF BERLIN, GERMANY, ASSIGIN'OR T BERGMAhl'N-ELEKTRICITATS- i WERKE, AK'IIENGESELLSCI-IAFT, OFIB ERLIN, GERMANY, A CORPORATION HIGHQPRESSUR-E STEAM :TURBIN E Application filed. February 10, 1925, Serial No. 8,250, and. in Germany February 22, 1924. I

for high steam pressure, it is advisable in order to obtain a'high efiiciency, to keep the blade diameter in the range of highest pres sure as small as possible. The reason for this is found therein, that for a given volume of steam a greater height of the turbine blades will be necessary. The clearance space will therefore become smaller with respect to the height of the blades and accordingly the losses due to clearance leakage will be decreased. Furthermore a smaller diameter of the blade rim will also cause a reduction in the losses due to friction and ventilation.

According to my invention the parts of the turbine which are under the highest pressure are preferably constructed as drum turbine.

the blade rim and a number of stages which is not too great, the speed of rotation of the high-pressure part of the turbine may be chosen higher than that of the subsequent stages. The high-pressure part is in this case arranged upon a special shaft, which is either connected with the shaft of the low-pressure part by means of a gear or which may be separated from the low-pressure part and drive a separate working machine.

In general the drum will have to be constructed with blades for over-pressure. Eventually, however, the drum may also be constructed with blades for even pressure. The employment of'over-pressure blades results in the especial advantage, that the relative velocity of the steam in the blades becomes smaller. This is of especial importance within the range of highest pressure in In order to obtain the smallest diameter of of the blades in view of the greater volume of steam for the diameter of the blade rim in the high-pressure part become too large and it will therefore be necessary to increase the diameter of the blade rim. For the greater diameter it would, however, be a disadvantage to retain the drum construction adapted for the high-pressure part, since this would cause impermissibly high clearance losses.

Within this range of pressure, therefore, ac

cording to my invention the turbine iscon- 1 7 structed as wheel-turbine, so thatthe' tightening betweenthe stages may againbe accomplished asmuch as possible in proximity to the shaft. v v

For the new turbine according to my invention it is therefore essential, that the high-' pressure part is constructed as drum-turbine, while the adjoining stages of the turbine are constructed as wheel turbine. The wheelturbine. may thus comprise all stages following the high-pressure part, and therefore also the entire low-pressure part. In the lowpressure part, however, the clearance losses on account of the smaller density of the steam, are no more of importance and therefore, for the low-pressure part eventually also a drum-turbine with large diameter may be employed.

In the drawing I have shown two examples of carrying out my invention. According to Fig. 1 the turbine consists of the high-pressure part a and the medium-pressure part 6, whereby the former is constructed as drum turbine and the latter as wheel-turbine, which are both mounted upon the same shaft. "In the construction according to Fig. 2, however, the high-pressure part a is mounted separately upon a shaft and the low-pressure part c is constructed as drum-turbine, so that only the medium pressure part b of the tur- Q1 H 1,756,814 E f bin'e is constructed as Wheel-turbine, which is locatedhetween the two drum-turbines. i

Iclai'mj 1 A high pressure steam turbine comprising 5 a drum'turbine for the high pressure stages,

a drum turbine forkthe 10 pressum stages, and a w'heel turbine 'fbr themediumipressure stages, saidwheeljturbine being arranged in- A V --.termediate said drum turbine and immediate 9 'ly iidjacfit.the'highkpressure.stage. I If testimony iwhereoffl'hav affix'ejd my, ".ff i fi fi i PAPE'. 

